Janet – in my opinion, the fact that the Council has supplied a certificate stating that the attic/storage area is not habitable doesn’t change the fact that the area and the access to it, whether that be by stairs or a drop-down ladder, is likely Common Property.
That makes your Owners Corporation (O/C) entirely responsible for the maintenance and repair of the above, provided you and the other Owners involved haven’t contributed to any damage such as the sagging to which your past posts have referred or haven’t used the area improperly such as by making it a habitable area, in which instances you could be held partly liable for rectification costs.
That, in my opinion, is why your O/C is pushing so hard to have you and the other Owners agree to a Special By-Law, which amongst other things seeks to make each of you liable for those maintenance and repair activities within the attic/storage area and the attached stairs/ladder for which it (the O/C) would be currently responsible IF those areas are as I suspect Common Property.
You’re seeking more expert advice, but in the meantime perhaps contact NSW Land & Property Information and seek their advice about the areas of your Plan that are shown as Common Property on the Strata Title Plan; they’re usually very helpful, but you may have to personally attend their Offices in this instance.
Finally, I know that you’ve been patient throughout this whole process, but I’d encourage you to look hard for a compromise, such as one the that I believe I suggested earlier whereby the O/C would make the necessary repairs to its Common Property attics / storage areas etc, after which the Owners would agree to the Special By-Law that thereafter transfers that responsibility to the individual Owners involved. Maybe talk to your Lawyer about that.
By the way, your experience at the NCAT is consistent with what too often happened in the old CTTT; as I said once before, different horse with the same jockeys.